#define _CRT_SECURE_NO_WARNINGS 1
#include<stdio.h>
#include<string.h>
void my_strcat(char *ch, char const *cat)
{
	int len1 = strlen(ch);
	int len2 = strlen(cat);
	int i = 0;
	int j = 0;
	for (i = len1; i < len1+len2; i++,j++)
	{
		*(ch + i) = *(cat + j);
	}
	*(ch + len1+len2 + 1) = '\0';
}

int main()
{
	char ch[80] = "\0";
	char cat[10] = "hello!";
	gets(ch);
	my_strcat(ch, cat);
	printf("%s\n", ch);
	return 0;
}